JP3106685B2 - Partial discharge measuring device for resin mold transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a partial discharge generated inside a winding of a resin-molded transformer.

[0002]

2. Description of the Related Art FIG. 5 is a front view showing a configuration example of a three-phase resin mold transformer. In the resin mold transformer, three-phase high-voltage windings 3 are wound around respective main legs of a tripod iron core 2 sandwiched between frames 1. The high-voltage winding 3 is formed by molding the entire winding conductor with epoxy resin, and has a substantially cylindrical outer shape. A low-voltage winding (not shown) is arranged on the inner diameter side of the high-voltage winding 3, and this low-voltage winding is also wound around the main leg of the iron core 2. A plurality of tap terminals 4 are provided outside each high-voltage winding 3, and are short-circuited via connection conductors 5. The inter-phase lead connection part 6 is an epoxy resin casting in which leads (not shown) for connecting the phases of the high-voltage winding 3 are embedded. The inter-phase lead connection section 6 is also provided with a high voltage terminal 7 for outputting a three-phase voltage to the outside.

[0003] The resin mold transformer is generally not housed in a dedicated tank, but is directly installed in a room or a switchboard. The tap change of the resin mold transformer is performed by the high voltage winding 3
Is set to a voltage-free state, and the connection is performed by connecting the connection conductor 5 to a predetermined tap terminal 4. FIG. 6 is a block diagram showing a method for measuring partial discharge of the resin mold transformer. This method is a method of detecting a partial discharge from a connection conductor 5 that short-circuits a tap terminal 4 of a high-voltage winding 3. The measurement of the partial discharge is performed by the partial discharge sensor 9 and the amplification unit 10,
E / O converter 11, optical fiber 12, O / E converter 1
3. The measurement is performed by the partial discharge measuring device 8 including the instruction unit 14.

[0006] In FIG. 6, the partial discharge sensor 9 is formed by a through-type current transformer, which penetrates the connecting conductor 5, and the secondary output thereof is sent to the amplifier 10. The amplifier 10 amplifies the input signal and outputs the amplified signal to the E / O converter 11. E / O converter 1
1 converts an input signal into an optical signal and outputs it to the optical fiber 12. The optical fiber 12 transmits an optical signal to the O / E converter 13. The O / E converter 13 converts the input optical signal into an electric signal and outputs the electric signal to the instruction unit 14. The instruction unit 14 displays the magnitude and frequency of occurrence of the partial discharge on a meter, an oscilloscope, or the like based on the input signal. in this way,
A method for detecting a partial discharge from the connection conductor 5 of the tap terminal 4 has already been filed by the same applicant as the present invention.
(JP-A-3-216564). By detecting the partial discharge current flowing through the connection conductor 5, the partial discharge generated inside the high-voltage winding 3 can be measured with high sensitivity. The partial discharge sensor 9 is sequentially connected again to the high-voltage winding 3 of each phase, and a total of three partial discharge measurements are performed.

FIG. 7 is a side view of a main part showing an example of a configuration of a conventional partial discharge measuring device for a resin mold transformer. A rod-shaped connecting conductor 5 is bridged between the tap terminals 4 provided on the high-voltage winding 3 of the resin mold transformer and bolted.
The partial discharge sensor 9 is passed through the connection conductor 5, and the output signal is received by the amplifier 10. The amplification unit 10 and the E / O conversion unit 11 are mounted on an insulating table 15 arranged on the ground 16. The output signal of the E / O converter 11 is transmitted via the optical fiber 12 to the O / E converter 1 on the ground 16.
3 receives. Furthermore, the indicator 14 receives the output signal of the O / E converter 13.

In FIG. 7, the reason why the insulating base 15 is necessary is that the amplifier 10 and the E / O converter 11
This is because they are at the same high potential. The amplifying unit 10 and the E / O conversion unit 11 also include batteries required for operation.

[0007]

However, the conventional apparatus as described above has a problem that the connecting conductor must be removed every time the partial discharge is measured. In order to make the partial discharge sensor penetrate the connection conductor, it was necessary to temporarily remove the connection conductor from the connection conductor and the tap terminal. In addition, in the case of a three-phase transformer, the connection conductor must be detached and attached three times to attach the partial discharge sensor to each high-voltage winding. Therefore, the preparation work required for the partial discharge measurement has taken time. In addition, the connection conductor is where the current flowing through the resin mold transformer flows, and if there is a failure in bolting, a serious accident may occur. Conventionally, after the measurement of the partial discharge, the operation of the resin mold transformer was restarted after carefully checking the attachment state of the connection conductor including the bolt torque management. It has been said that it is preferable not to remove the connection conductor as much as possible.

An object of the present invention is to enable partial discharge measurement without removing a connecting conductor.

[0009]

According to the present invention, there is provided a non-voltage switching type tap terminal on the high voltage winding side, and the tap terminals are short-circuited by a connection conductor. An apparatus for measuring a partial discharge of a resin mold transformer, a partial discharge sensor including a through-type current transformer penetrating the connection conductor, an amplifying unit that amplifies an output signal of the partial discharge sensor, and An E / O converter for converting the output signal of the amplifier to an optical signal; an optical fiber for transmitting the output signal of the E / O converter; and an O for converting the optical signal transmitted by the optical fiber to an electric signal. / E converter and the O /
An indicator for displaying the magnitude of the output signal of the E-converter, wherein the connection conductor and the partial discharge sensor are integrally formed, and the amplifier and the E / O converter are integrally formed; The output terminal of the partial discharge sensor and the input terminal of the amplifying unit form a pluggable connector that can be fitted to each other.
It is assumed that the integrated unit of the / O conversion unit is supported on the resin mold transformer side only by fitting the plug-in connector.

[0010]

According to the structure of the present invention, the connection conductor and the partial discharge sensor are integrated, and the amplifier and the E / O converter are also integrated. Further, the output terminal of the partial discharge sensor and the input terminal of the amplification section are formed in a pluggable connector that can be fitted to each other. According to this configuration, since the partial discharge measurement only needs to be inserted into the connector, it is not necessary to remove the connection conductor.

Also, in addition to the above configuration, an amplification unit and an O / E
The integrated converter is configured to be supported on the resin mold transformer side only by fitting the plug-in connector. This eliminates the need for an insulating table during the partial discharge measurement, thereby reducing the number of components of the measurement jig. Further, in addition to the above configuration, the periphery of the partial discharge sensor was covered with a connection conductor. With this configuration, the partial discharge sensor cannot be seen from the outside of the resin mold transformer, so that the aesthetic appearance of the transformer during operation can be maintained.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is a side view of a main part showing a configuration of a partial discharge measuring device for a resin mold transformer according to an embodiment of the present invention. A connection conductor 17 containing a partial discharge sensor inside is attached between the tap terminals 4, and an E / O conversion unit 18 containing an amplification unit on the input side inside via a connector 19 is connected to the high voltage winding 3.
Supported on the side. Other configurations are the same as the conventional one. Therefore, the same parts are denoted by the same reference numerals, and detailed description is omitted.

FIG. 2 is an enlarged sectional view showing the structure of the connection conductor 17 of FIG. 1, and FIG. 3 is a sectional view taken along line XX of FIG. In FIG. 2, two cylindrical portions 17A and 17B in which the connection conductor 17 contacts the tap terminal 4, and the cylindrical portions 17A and 17B
And a connecting portion 17C for electrically connecting the two. The connection conductor 17 is fixed to the tap terminal 4 via a bolt 20 penetrating through the hollow portions of the cylindrical portions 17A and 17B. The connection conductor 17 houses the partial discharge sensor 21 via a supporting insulator (not shown). Partial discharge sensor 2
Reference numeral 1 denotes a toroidal ferrite portion 21A surrounding the outer periphery of the cylindrical portion 17A, and a secondary winding 21B winding the ferrite portion 21A. The connection conductor 17 is further provided with a receptacle 22. The receptacle 22 includes an inner conductor 22A having a fitting hole at the center.
And an outer conductor 22C arranged on the outer periphery of the inner conductor 22A via an insulation 22B. Outer conductor 22C
Is provided with a threaded portion on the outer periphery, and an insulating ring 22
It is fixed to the connection conductor 17 by a nut 22D via E. The output side of the secondary winding 21B is connected to the receptacle 2
The second inner conductor 22A and the second outer conductor 22C are conductively connected to each other, and are electrically insulated from the connection conductor 17.

In FIG. 3, the connecting portion 17 of the connecting conductor 17 is shown.
C has a shape in which one side is spread because the partial discharge sensor 21 is built in. The current output from the tap terminal 4 of the high-voltage winding 3 is applied to the cylindrical portion 17A of the connecting conductor 17 and the connecting portion 17.
C, flows through the cylindrical portion 17B, and flows into another tap terminal 4. Since a current flows through the cylindrical portion 17A penetrating the center of the ferrite portion 21A, an electric signal is induced in the secondary winding 21B when a partial discharge occurs in the high voltage winding 3, and the electric signal is transmitted to the inside of the receptacle 22. Output to conductor 22A and external conductor 22C.

FIG. 4 is an enlarged sectional view of a main part showing the configuration of the E / O converter 18 in FIG. E / O converter 18 is case 2
3 includes an amplifying unit, an E / O converting unit, and a battery (not shown). Plug 24 into the opening of case 23
It has. The plug 24 has a needle-shaped inner conductor 24 at the center.
A and an outer conductor 24C arranged on the outer periphery of the inner conductor 24A via an insulation 24B. Outer conductor 24
C has a threaded portion on the outer periphery and an insulating ring 2 having a U-shaped cross section.
It is fixed to the case 23 by a nut 24D via 4E. The inner conductor 24 </ b> A and the outer conductor 24 </ b> C are connected to the amplification section inside the case 23 while being insulated from the case 23. The plug 24 shown in FIG. 4 and the receptacle 22 shown in FIG. 2 can be fitted together. When fitted together, the connector 19 is formed as shown in FIG.
8 is fixed to the high voltage winding 3 side.

When the connector 19 is connected, the internal conductor 24A of the plug 24 in FIG. 4 is just fitted into the fitting hole of the internal conductor 22A of the receptacle 22 in FIG. 2, and the external conductor 24C of the plug 24 is connected to the receptacle. 22 fits outside the outer conductor 22C. Therefore, the E / O converter 1
8 can be easily attached to and detached from the connection conductor 17 by hand. Moreover, if the E / O conversion unit 18 is removed, the resin mold transformer can be operated while the connection conductor 17 is attached to the high-voltage winding 3.

As shown in FIG. 1, in order to fix the E / O converter 18 to the high-voltage winding 3 only with the connector 19, the E / O converter 18 is made as compact and lightweight as possible. Better. Therefore, the case 23 of the E / O converter 18 may be made of, for example, a lightweight ABS resin.
If the case 23 is insulating, the plug 24 in FIG.
The insulating ring 24E is unnecessary.

The partial discharge sensor 21 does not necessarily have to be housed inside the connection conductor 17 as shown in FIG. The point is that the partial discharge sensor 21 may penetrate the connection conductor 17 and be fixed integrally with the connection conductor 17 and have a receptacle 22 that outputs a detection signal of the partial discharge. However, by covering the partial discharge sensor 21 with the connecting portion 17C of the connection conductor 17 as shown in FIG. 2, the partial discharge sensor 21 becomes invisible from the outside, and the aesthetic appearance of the operating transformer can be maintained.

[0019]

As described above, according to the present invention, the connecting conductor and the partial discharge sensor are integrated, and the amplifying unit and the E / O
The conversion unit is also integrally configured. Further, the output terminal of the partial discharge sensor and the input terminal of the amplification section are formed in a pluggable connector that can be fitted to each other. According to this configuration, since the partial discharge measurement only needs to be inserted into the connector, it is not necessary to remove the connection conductor. Therefore, the preparation time for the partial discharge measurement is reduced, and the connection failure of the connection conductor to the tap terminal and the selection of the tap terminal are completely eliminated.

Further, in addition to the above configuration, an amplification unit and an O / E
The integrated converter is configured to be supported on the resin mold transformer side only by fitting the plug-in connector. This eliminates the need for an insulating table during the partial discharge measurement, thereby reducing the number of components of the measurement jig. Further, in addition to the above configuration, the periphery of the partial discharge sensor was covered with a connection conductor. As a result, the partial discharge sensor becomes invisible from the outside of the resin mold transformer, so that the aesthetic appearance of the transformer during operation is maintained.

[Brief description of the drawings]

FIG. 1 is a main part side view showing a configuration of a partial discharge measuring device for a resin mold transformer according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a configuration of a connection conductor of FIG. 1;

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is an enlarged sectional view of a main part showing a configuration of an E / O converter in FIG. 1;

FIG. 5 is a front view showing a configuration example of a three-phase resin mold transformer.

FIG. 6 is a block diagram showing a method for measuring partial discharge of a resin mold transformer.

FIG. 7 is a side view of a main part showing a configuration example of a conventional partial discharge measuring device for a resin molded transformer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frame 2 Iron core 3 High voltage winding 4 Tap terminal 12 Optical fiber 13 O / E conversion part 14 Indicator part 16 Ground 17 Connection conductor 17A Cylindrical part 17B Cylindrical part 17C Connection part 18 E / O conversion part 19 Connector 20 Volt 21 Partial discharge Sensor 21A Ferrite part 21B Secondary winding 22 Receptacle 23 Case 24 Plug 22A Inner conductor 24A Inner conductor 22B Insulation 24B Insulation 22C Outer conductor 24C Outer conductor 22D Nut 24D Nut 22E Insulation ring 24E Insulation ring

Continuation of front page (56) References JP-A-3-216546 (JP, A) JP-A-64-15670 (JP, A) JP-A-56-88626 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01R 31/12

Claims (3)

(57) [Claims] 1. An apparatus for measuring a partial discharge of a resin mold transformer having a non-voltage switching type tap terminal on a high voltage winding side, wherein the tap terminals are short-circuited by a connection conductor. A partial discharge sensor composed of a through-type current transformer penetrating the connection conductor, an amplifier for amplifying an output signal of the partial discharge sensor, an E / O converter for converting an output signal of the amplifier into an optical signal, An optical fiber for transmitting an output signal of the E / O converter, an O / E converter for converting an optical signal transmitted by the optical fiber into an electric signal, and a magnitude of an output signal of the O / E converter And a connecting part and the partial discharge sensor are integrally formed, and the amplifying part and the E / O conversion part are integrally formed, and the output end of the partial discharge sensor and the partial discharge sensor are displayed. A plug that can be mated with the input end of the amplifier Partial discharge measuring device of the resin mold transformer, characterized in that by forming a shape connector. 2. An amplifier according to claim 1, wherein said amplifier is
A partial discharge measuring device for a resin-molded transformer, wherein an integrated unit of the / O converter is supported on the resin-molded transformer side only by fitting of a plug-in connector. 3. The method according to claim 1, wherein
A partial discharge measuring device for a resin mold transformer, wherein a periphery of the partial discharge sensor is covered with a connection conductor.